In Madadia, a rather strange and misguided assassin, from his hidden position, uses a high-powered rifle to shoot someone in the foot from 50 feet away. The bullet travels at 1300 feet per second. Both the person being shot at and the assassin are at sea level. What will be the first evidence to the person of the attack?

Answer

Although being a mixed-up assassin, the body does state that he hid himself well and you did not see the actual flash of the gun (and for some reason was aiming for your foot). The speed of sound is approximately 1129 feet per second at sea level. The sound will reach the target's ears in .044 seconds. The bullet will hit his foot in .038 seconds. So much for dodging the bullet on this one. But I asked which would be the first evidence to the person of the attack
- and that would be the sound, because once the bullet hits his foot, the pain impulse must travel the myelinated A-fibers to his brain at 330 feet per second. Assuming he is at least five feet tall, that's an extra .015 seconds onto the trip.Hide

Comments

First, how long does it take the nerve impulses to travel from his ears to his brain? Second, there would still be evidence to the person from the foot first, even if not the person's brain; though that's really one for the philosophers.

My thinking exactly... I'm pretty sure it would take just as long (if not longer..) for the sound to be interpreted by his brain..

Really, though, I could be 100% wrong, but are nerves really straight up and down like that? I mean, aren't they in bundles, and wind all around..? I'm pretty sure that from head to foot, there is not only 5 feet of nerves.. more like 50 feet (just a guess, I have no real idea).

My thinking exactly... I'm pretty sure it would take just as long (if not longer..) for the sound to be interpreted by his brain..

Really, though, I could be 100% wrong, but are nerves really straight up and down like that? I mean, aren't they in bundles, and wind all around..? I'm pretty sure that from head to foot, there is not only 5 feet of nerves.. more like 50 feet (just a guess, I have no real idea).

My thinking exactly... I'm pretty sure it would take just as long (if not longer..) for the sound to be interpreted by his brain..

Really, though, I could be 100% wrong, but are nerves really straight up and down like that? I mean, aren't they in bundles, and wind all around..? I'm pretty sure that from head to foot, there is not only 5 feet of nerves.. more like 50 feet (just a guess, I have no real idea).

Why do we assume that a pain impulse travels at the speed of sound? I highly doubt pain happens to travel at the exact speed of sound, since it is not traveling in waves as such. The pain in the foot would be the first thing he noticed.

Mad Ade was actually saying pain travels slower than the speed of sound (330 ft/s vs 1129 ft/s). He was merely showing that the pain would take longer to reach his brain. However, one thing he didn\'t consider is that the impact of the bullet with the victim\'s foot would also make a sound. The sound of the bullet\'s impact with the victim\'s foot would reach his ears before the shot\'s sound, even if the shot is fired from ear level, provided the victim\'s ears are no more than about 6\'4\" from his feet (if I figured this out right).

How about the autonomous nervous system? According to my high-school biology, the fastest nerve reaction would travel from the injured tarsal nerve, up to the iliac bundle (nerves at the base of the spinal cord). Here, the autonomous bundle would recognize the pain and send contraction signals to the leg muscles, and the first to fire would be the femoral muscles (quadriceps and friends).
This might not change the ultimate answer, depending on how long it takes the victim to realize that his leg has moved. If he senses it visually, we've shortened the critical path here by about 20% of the nervous transit time. If he senses the movement through physical change transmitted through his body (the "self-quake" as his leg jerks, probably felt first through the cochlea's balance system), then I don't know enough to estimate the transit time. I'd guess it to be on the close order of the speed of sound through water, but my error factor is larger than the difference in the two transit figures presented in the teaser's answer.

actually, with an intense traumatic pain, the brain is extremely slow in recognizing it. its like a safety feature. so they guy probably would hear the gunshot first, then feel the pain (if he feels it at all). i didnt get it, but it makes sense to hear then feel. i think.

on the pain issue it depends on the person. I do have to say that a high powered rifle at 50ft will probably take off his entire foot and jerk his entire leg and probly jerk his whole body about. I would say that he would notice that a lot more than the gun shot.

In fact if that happened to me I might not even notice the sound seing in about 2 seconds I would be partly spun around an fallen on the ground with intense pain in my foot.

Oh and anny ASSASSIN would use a silencer which would make a quiet pfft sound. also ASSASSINS generaly use 50cal rifles definately taking off the foot and more regardless of how miss guided he is.

Now that everyone tried to demoralize this teaser, I thought it was good. I'd like to say to everyone who said the noise of the bullet reached his ear first that it wouldn't be as noticable in the .00 whatever seconds. Also even if his foot was ripped off and it exploded I think he wouldn't spin around and do whatever in a fraction of a second. It was great, another good teaser from Mad ade